Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
There is a typical image forming apparatus that converts colors of images for a print job. The typical image forming apparatus obtains correction coefficient for each specific region based on lightness of the specific region in an image, and then changes the lightness of the specific region with the obtained correction coefficient when printing an image where characters and objects with dark colors such as black and dark blue are present in a dark background such as a background at nighttime. The typical image forming apparatus improves a lightness difference of a low lightness part in an image to distinguish characters and objects from a background, thus ensuring visibility.